Results 1 to 10 of about 1,399 (81)
Spatiotemporal changes of construction land expansion in Hangzhou city(杭州城市建设用地扩张的时空演变分析)
Zhejiang Daxue xuebao. Lixue ban, 2022 基于杭州市1914—2018年间6期近代地图与遥感影像数据，通过目视解译数字化的近代地图，使用面向对象的分类方式对CORONA、Landsat TM和OLI影像进行分类并提取建设用地数据，计算扩张速度、重心变化、景观格局指数和增长类型，分析建设用地的扩张过程与扩张模式。结果表明：（1）近百年来杭州城市建设用地扩张明显，扩张过程主要集中在改革开放后。（2）杭州城市重心经历了“北—西北—北—东南—南”的变化过程，由向单一方向扩张转变为多方向均衡发展的态势。（3）建设用地扩张过程基本符合“扩散—融合”假说 ...
LUHuan(卢奂) +2 more
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The impact of implicit debt on cities′spatial expansion(隐性债务对城市空间扩张的影响研究)
Zhejiang Daxue xuebao. Lixue ban, 2022 为推动城市开发与基础设施建设，满足城市新增人口的公共服务需求，地方隐性债务规模快速增长，经济下行加剧了地方政府所面临的债务风险。利用2007—2018年我国285个地级市隐性债务数据，采用固定效应模型，从债务规模与发债主体特征两个视角评估隐性债务对城市空间扩张的驱动机制。主要结论有：（1）隐性债务规模对城市空间扩张有显著正向影响，上期隐性债务规模的增加将推动当期城市建成区扩张。发债规模增加1亿元，城市建成区面积增加0.192 km2，“借债建城”成为地方政府推动城市空间扩张的主要模式。（2 ...
ZHANGJuanfeng(张娟锋) +3 more
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Zhejiang Daxue xuebao. Lixue ban, 1999 从生物硝化池污水水样中分离了硝化细菌DNA，以其为模板，针对其16SrRNA基因及23SrRNA基因而设计合成了两对引物并分别进行了PCR扩增，扩增产物的2%琼脂糖凝胶电泳结果显示，硝化细菌DNA模板得到了特异性扩增.参照分子量标准（Marker）的电泳结果，被扩增的DNA条带大小分别约为400bp和730bp.实验结果表明PCR 技术可用于污水中硝化细菌的快速检测.
MINGZhen-huan(明镇寰) +3 more
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Zhejiang Daxue xuebao. Lixue ban, 2005 研究用分阶段共培养法进行体外扩增的脐血造血干/祖细胞对NOD/SCID小鼠重建造血功能的作用，探讨新扩增技术体系对将来临床移植的可行性.分离脐血单个核细胞，分别用rhSCF+rhG-CSF+rhMDGF组合（非共培养组合）和rhSCF+rhG-CSF+rhMDGF+人骨髓间充质干细胞组合（共培养组合）进行脐血造血干/祖细胞的体外扩增，并对扩增细胞进行流式细胞术和细胞集落形成能力分析.在移植实验中，将经致死剂量射线照射后的NOD/SCID小鼠随机分为3组，每组10只.A组：每只移植8.5 ...
WANGJin-fu(王金福) +3 more
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Zhejiang Daxue xuebao. Lixue ban, 2016 在当前高速城市化的背景下，为及时了解嘉兴市的城市发展现状，使用遥感手段提取各时间段内城市的建设区域，并分析了扩张过程的时空特征，再结合社会经济数据探究了城市扩张的驱动力因素.结果表明：嘉兴市在1993〜2013年间城市扩张明显，扩张速度和强度先增后减，扩张方向由西北转向南，扩张模式经历了“主动型-被动型-稳定型”的转变过程，扩张合理性较差，城市扩张速率高于人口增长速率，扩张驱动因子主要为经济发展、产业结构调整和人口增长.
CHENKexin(陈可欣) +3 more
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Rare Metals, EarlyView.ABSTRACT Internal oxidation has been identified as an effective method for enhancing the strength of AgMg alloys. However, the concurrent occurrence of embrittlement remains inadequately understood, thus limiting their broader application. This study investigates the oxidation behavior of AgMg alloys with Mg concentrations ranging from 1 at% to 7 at ...
Hai‐Cheng Zhu +12 more
wiley +1 more source
Rare Metals, EarlyView.ABSTRACT The high accuracy in surface‐enhanced Raman scattering‐lateral flow immunoassays (SERS–LFIAs) is critical for reliable point‐of‐care testing (POCT) in clinical diagnostics. Conventional approaches are often affected by sampling variability and uneven distribution of immunoprobes, leading to unreliable signal fluctuations.
Shuai Zhao +9 more
wiley +1 more source
Rare Metals, EarlyView.ABSTRACT The development of high‐performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs.
Changlong Du +9 more
wiley +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2005 探讨来自脐血的贴壁细胞的特征及其对脐血造血干/祖细胞体外扩增的支持作用.利用流式细胞术对脐血中培养出的贴壁细胞进行了鉴定，同时观察其形态学特征，并由此建立细胞饲养层；在饲养层基础上建立共培养体系，分别体外扩增单个核细胞和CD34+细胞，观察饲养层对体外扩增的影响，并检测扩增后细胞的GEMM-CFC形成潜能.结果表明，脐血贴壁细胞呈纤维状，其CD14阳性细胞仅3.8%，而CD13、CD166、CD29阳性细胞分别为51.8%、35.6%、16.5%；与仅用外源细胞因子的非共培养体系相比 ...
WANGLi-juan(王丽娟) +7 more
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Rare Metals, EarlyView.ABSTRACT The polyanionic compound Na3V2(PO4)3 (NVP) has emerged as a competitive cathode material for sodium‐ion batteries (SIBs), owing to its high‐voltage redox activity (3.4 V vs. the Na+/Na reference couple) and NASICON‐type framework that enables superior ionic conductivity.
Xiaolei Wu +5 more
wiley +1 more source